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Notes from Fall, 2015 MIAAPT Meeting

I have been meaning to post my notes from the delightful Fall MIAAPT meeting at Interlochen Arts Academy! Here they are. As always, my notes are my notes – accuracy is not guaranteed. Here also is a photo of the venue.

The title says what he was after – making his classroom a sort of perpetual conversation between instructor and student. One method he uses to achieve this is a “reflection activity” where students work on a problem, then find answer keys and orange pens around the room. In addition to correcting their work, they are asked to answer…

What did you do well?

What preparation enabled this?

How could you improve?

The activity is very low-stakes gradewise, graded satisfactory/unsatisfactory (and essentially anyone who tries is graded satisfactory, he implied). He is also adapting the process to exams. Perhaps do a small group review of an exam without, and then with, a solution. Corrections do not modify the exam score. Also on homework he does a regradeable “hand-in” problem in addition to the online system they use, and he also does quizzes with immediate instructor feedback.

If I recall, his classes are a good deal larger than we have at LCC, as much as that may matter.

Michael Faleski, Delta College, “Rolling with and without slipping”

This was a sort of follow-on to a talk he gave at a previous MIAAPT meeting where an apparently simple question provoked quite the discussion. If you have a ring and a disk of the same mass roll down a hill, on which object is the force of friction the greatest? (The ring – as shown by the fact that it takes longer to get down the hill.) Suppose instead both roll at a constant speed on a horizontal surface? (In this case they are tied – in fact the friction on both is zero.) Suppose instead you have two disks, one on a surface with friction and one without. Both feel a constant horizontal force on top of the disk to the right and begin moving – which disk experiences the greater acceleration? (The disk on the surface with friction, because friction is an additional horizontal force to the right.)

He then shared quite the fascinating “phase diagram” (and HTML5 applet he developed) for the different motions possible for a disk. What he did was imagine applying a horizontal force to a disk at a variable position above and below the center of mass of the disk, and he also imagined being able to vary the coefficient of static friction. And what he got was a phase diagram describing which way the disk would rotate, and whether it would experience static or kinetic friction. I’m sure if emailed he would share the phase diagram and applet, neat stuff. He is still thinking about what this means for energy analysis.

Showed off lots of examples of how a 3D printer could be used in Physics. Most intriguing to me was a project he did with his students studying how the shape of a wind turbine blade affected power output, with 3D printed blades. “Tinkercad”, “OpenSCAD”, and “Thingaverse” are three resources he utlizes. After the Rosetta landing he printed out a 3D printed version of the comet to discuss it in class. He has also printed air-track sliders and clip-on weights. I left this talk quite convinced there is a lot we could easily do with 3D printing.

Lauren DeVries and Christopher Nakamura, Saginaw Valley State University, “Student Reasoning in Chemistry: A Work in Progress”

A talk which discussed, among other things, how physics majors seem to reason (from principle) verses chemistry majors (from experience). Example – a graduated cylinder is filled to the 100 mL line, and the water is then dumped into a beaker. In the beaker, the water level lies below the 100 mL line – is this possible? Physics majors tended to answer no, that would violate conservation of volume. Chemistry majors tended to answer yes – beakers are labelled less precisely, and haven’t I seen water get stuck in the cylinder in lab? Also mentioned chemistry students tend to struggle with inverse relationships (energy and wavelength, for example).

Michael LoPresto, Henry Ford College, “Hearing the Music in the Spectrum of Hydrogen”

Mentioned that students often find the analogies of…

Color <-> Pitch

Brightness <-> Loudness

Hue <-> Timble

helpful. But what I found especially fascinating was that he looked at the frequencies in the hydrogen spectrum and noticed that the ratio between them was the same as the ratio between some musical notes, making it possible to imagine literally playing hydrogen on a keyboard. Which he did. It sounded spooky.

A summary of a talk he gave at national AAPT about how to transition from the “old-style” of lecture only to new active learning styles. Suggested beginning with reading quizzes, a 1-2 minute question at the beginning of class (and such questions are often included with textbooks nowadays). Then moving on to think/pair/share “clicker” questions. They moving on to include Ranking Tasks. Then revisit your lab materials – shoot to get some discrepant events (don’t just have them measure g… again), predict before outcomes, let them design the experiment. You can find good stuff on Compadre. Then begin using lecture-tutorials, let students construct the concepts for themselves – the University of Maryland has good stuff. Finally start doing studio instruction, integrating lab and lecture. But always remember, if you don’t get your way – teach by any means necessary.

How to incorporate art into your Physics class? Nadji was especially influenced by the book “The Intelligent Eye” – learning to think by looking at art.

One thing he does, when beginning a new section in Physics, is have them look at a piece of art or listen to a piece of music – like this one, for example: http://www.wikiart.org/en/kazimir-malevich/floor-polishers-1912 . He then has students answer, individually, three questions. What is the period of the painting? What is the title? What are the physics connections (at least three)? He then calls on students to answer through a set of index cards – he also has some group work and grading to teach students to listen to each other.

Another piece he has them look at is this one: http://www.wikiart.org/en/vincent-van-gogh/the-starry-night-1888-2 . Here he asks them to come up with three astronomy questions provoked by the piece, and asks them to answer one of their own questions. He also has them use the app “Planets” to try to figure out when exactly Van Gogh painted this piece based on the stars and the sky, and the students learn the painting is impossible! Ursa Major would have been behind Van Gogh, not in front of him!

Also suggested having students use their cell phone as a source at the optical bench. Hey, we could 3D print a holder.

Michael LoPresto, Henry Ford College, Worshop, “Teaching a General Education Sound and Light Course for Music and Art Students”

He teaches a course on the physics of art and music.. The most fascinating part of his workshop for me was his mention of Fletcher-Munson curves (look ’em up), which show how loud a sound appears to humans as a function of frequency. The graph shows loudness peaks near 4000 and 12000 Hz – which turn out to be the first and third harmonics of an ear canal resonance! You could calculate the size of your ear canal based on how loud things sound, neat.

Puzzlers Session

Larry Tarini asked the question – given Newton’s Third Law, why is a headbutt ever a good idea as an offensive/defensive move? Suggestions were that the preparation the attacker has makes the headbutt go better for him, and he also controls where on the heads the impact happens! Nadji mentioned that in Algeria the person giving the headbutt aims for the other person’s nose! There was much joking about just how often physicists find themselves in physical combat.

The keynote was about solar physics and space weather. She described the sun as dynamic for three reasons – it is composed of plasma, it has a strong magnetic field, and it has differential rotation which causes the magnetic fields to get all twisted up just like those old phone cords that your students have never seen. And there are still plenty of mysteries too – the coronal heating problem, for example. Why is the sun’s corona so much hotter than the surface? Some of the sun’s most energetic events are tied to magnetic reconnection events, and exactly what is happening “microscopically” when these field lines “connect” and reform is also unknown.

Magnetic reconnection events turn magnetic energy into thermal and kinetic energy and are tied to solar flares and coronal mass ejections. Flares occur near sunspots because that is where the field is bundled. I found the numbers impressive – X-flares are very powerful and output 10^20 W. Lasting minutes or hours they release 10^25 J, 20,000 times Earth’s yearly energy production, making them the most energetic objects in the solar system.

While solar flares might be mainly radiation, coronal mass ejections are more “stuff” and thus travel more slowly and give some warning before their arrival. She shared some cool videos you can find on the Goddard Youtube channel.

Prominences, on the other hand, are relatively cooler bits of plasma hanging out just above the solar surface. They have a helical structure that results from following the magnetic field line that is actually visible in some photos. Quite cool. They live for hours or months.

Sunspots (and solar activity) occur in an 11 year cycle, and we have data going back to 1700 (poor early blind scientists). We are currently leaving a relatively weak maximum. In the 1600s there was a 50 year period with almost no sunspots that corresponded to the Little Ice Age.

Space weather impacts include aurora, resulting from charged particles interesting with our atmosphere. Green aurora occur from 100km-200km up, red >200 km. Satellites can also have problems, and there are astronaut health effects. In 1989 there was a large power outage in Quebec because of a solar storm. Earth impacts can be hard to predict because, for example, the magnetic field of a CME must be oppositely oriented to the field of Earth to cause magnetic reconnection events. NASA also studies space weather on other planets because they have assets there.